1. Field of the Invention
The present invention relates to a monoclonal antibody which specifically recognizes a synaptophysin.
2. Description of the Related Art
A synaptophysin was found in a bovine brain by wiedenmann et al. in 1985 (Cell, 41, 1017-1028), the synaptophysin being an acidic glycoprotein which is present on the membrane of a synaptic vesicle and has a molecular weight of about 38,000. On the other hand, a P-38 was found in a rat brain by Jahn et al. in 1985 (Proc. Natl. Acad. Sci. USA, 82, 4137-4141). However, when nucleotide sequences of the synaptophysin and the P-38 were analyzed, they were found to be identical proteins.
Since the synaptophysin and the P-38 locally exist in synaptic vesicles, they are used as detection markers for a neuroendocrine tumor which holds synaptic vesicles. The neuroendocrine tumor is formed in endocrine organs having synaptic vesicles such as a pituitary gland and a pancreas, but the tumor is metastasized to a organ other than the endcrine organ, which has no synaptic organs. If the synaptophysin is detected in an organ having no synaptic vesicles, it is understood that the organ holds the tumor and that the tumor is metastasized from the endcrine organ mentioned above. Thus, the synaptophysin specific monoclonal antibody of the present invention is useful to locate a primary focus of the neuroendocrine tumor.
At present, commercially available monoclonal antibody for the synaptophysin or the P-38 is monoclonal antibody which belongs to an immunoglobulin class G.
Since the conventional known monoclonal antibody for the synaptophysin belongs to an immunoglobulin class G, only two binding sites for antigen and complement are present within each molecule. For this reason, in order to quantitatively analyze a very small amount of synaptophysin in tissues in accordance with a complement fixation test, a large amount of the antibody is required, resulting in inconvenience.